• 한국컴퓨터정보학회논문지
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• 제28권3호
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• pp.177-187
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• 2023

이 연구는 교육서비스 관점에서 MOOC의 질 평가를 위한 잠재모형을 도출하고 신뢰롭고 타당한 MOOC 질 평가도구를 개발하고 타당화하는 데 목적이 있다. 연구목적을 달성하기 위해 선행 연구결과에 기초해서, MOOC 평가 잠재모형(4개 요인과 8개 하위요인)을 도출하였다. 이 잠재모형을 토대로 18개 예비 평가문항을 개발한 후, 대학 원격수업 경험이 있는 학습자 138명을 대상으로 문항중요도 설문을 실시하였다. 수집된 136개의 자료를 활용하여 탐색적 요인분석 결과, 수집된 데이터에서 4개의 요인(체제적 학습 경험, 가치 경험, 가치 경험의 공동 창조, 고차원 학습경험)과 7개의 하위요인(실제성, 신뢰성, 확신성, 반응성, 조직환경 체계성, 프로그램 체계성, 학습자 지지의 체계성, 공동주도성)으로 추출되었다. 신뢰도 분석결과, 선정된 문항들은 각 척도를 구성하는 문항으로서 높은 내적합치도를 보였다. MOOC에 대한 평가도구는 타당하고 신뢰할 수 있다는 결론을 내릴 수 있다.

• 한국환경과학회지
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• 제17권5호
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• pp.485-491
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• 2008

The present study examined the relation between land cover condition and temperature in various types of urban green spaces. The diagram of temperature distribution showed that high-temperature zones are formed around paved areas, and low temperature zone around planted areas and grassy areas. Even in planted areas where low-temperature zones were formed, temperature was different according to hierarchical structure. That is, temperature was relatively low in areas covered with arbor + sub-arbor. With regard to land cover ratio, the increase of planted areas and grassy areas had an effect on the fall of temperature and the effect was higher in order of planted areas and grassy areas. On the contrary, paved areas and bare areas had an effect on the rise of temperature. According to the results of factor analysis, in case of the highest temperature, planted area and grassy area were put together into a factor lowering temperature, paved area and temperature into a factor raising temperature, and bare area alone into a factor of low significance. In case of the lowest temperature, grassy area and bare area were put together into a factor, and the validity of the factor analysis was proved by the analysis of urban heat islands. An increase in the number of trees by height was effective in lowering temperature, and the effect was high in order to arbor and sub-arbor, and the source of coldness in planted area was tall trees.

• Steel and Composite Structures
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• 제45권3호
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• pp.305-330
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• 2022

This article aims to investigate the static deflection and stress analysis of bi-directional functionally graded porous plate (BDFGPP) modeled by unified higher order kinematic theories to include the shear stress effects, which not be considered before. Different shear functions are described according to higher order models that satisfy the zero-shear influence at the top and bottom surfaces, and hence refrain from the need of shear correction factor. The material properties are graded through two spatial directions (i.e., thickness and length directions) according to the power law distribution. The porosities and voids inside the material constituent are described by different cosine functions. Hamilton's principle is implemented to derive the governing equilibrium equation of bi-directional FG porous plate structures. An efficient numerical differential integral quadrature method (DIQM) is exploited to solve the coupled variable coefficients partial differential equations of equilibrium. Problem validation and verification have been proven with previous prestigious work. Numerical results are illustrated to present the significant impacts of kinematic shear relations, gradation indices through thickness and length, porosity type, and boundary conditions on the static deflection and stress distribution of BDFGP plate. The proposed model is efficient in design and analysis of many applications used in nuclear, mechanical, aerospace, naval, dental, and medical fields.

• 한국의류학회지
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• 제27권1호
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• pp.143-153
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• 2003

This study was conducted in order to provide basic study material for children's garment design. The subjects of this study are fifth and sixth grade elementary school girls, who demonstrate rapid growth and the differences among individual somatic types are apparent. Their bodies are studied, categorized into patterns and the characteristics are examined. 1 The increase of height and length measurements according to age increase are much larger than that of breadth, depth and girth menasurments. 2. Eight factors are drawn upon factor analysis and the rate of factors comprisedare 78.68%. 3. The shapes of lower body of higher grades girls in elementary school are classified into three categories. The first type is slender in lower body and the second type is more contoured around waist area with longer length and higher height than the average elementary school girls. The third type is heavy in the lower body. 4. Eighteen items important for somatic categorization are selected through stepwise discriminant analysis and the exactitude rate of these items is 93.3%.

• 한국임상보건과학회지
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• 제6권2호
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• pp.1126-1135
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• 2018

Purpose. The purpose of this study is to investigate the success model related to the hospital information system accomplishment. It is important to examine the success model of the hospital information system and to analyze the factors affecting the job satisfaction accomplishment. Methods. The method of this study is to 150 copies of the entire survey data were distributed and 135 copies were collected, showing a collection rate of 90%. In order to ensure the reliability of the questionnaire items, Cronbach's Alpha was used to test reliability, and exploratory factor analysis was conducted to determine the convergence of various items. In order to grasp the convergence of various items, exploratory factor analysis was performed. The results of exploratory factor analysis were used to analyze the correlations between variables that were proven to have a single dimensionality before calculating factor loadings and regression analysis by Orthogonal Rotation by Varimax method Results. The results of this study, first, the system quality of the hospital information system has a statistically significant effect on user satisfaction. Second, the information quality of hospital information system is statistically significant for user satisfaction, indicating that information quality improves user satisfaction. Third, service quality of hospital information system was statistically significant in user satisfaction. Finally, the higher the satisfaction of the users who use the hospital information system, the higher the accomplishment of the organization Conclusions. This study is based on the successful model of D & M information system. In addition, the hospital information system, the user satisfaction, and the organizational accomplishment in connection with it can be found significant.

• Journal of electromagnetic engineering and science
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• 제13권3호
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• pp.158-164
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• 2013

This paper expands a previously proposed optimized higher order (2, 4) finite-difference time-domain scheme (H(2, 4) scheme) for use with lossy material. A low dispersion error is obtained by introducing a weighting factor and two scaling factors. The weighting factor creates isotropic dispersion, and the two scaling factors dramatically reduce the numerical dispersion error at an operating frequency. In addition, the results confirm that the proposed scheme performs better than the H(2, 4) scheme for wideband analysis. Lastly, the validity of the proposed scheme is verified by calculating a scattering problem of a lossy circular dielectric cylinder.

• Journal of Power Electronics
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• 제12권5호
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• pp.689-698
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• 2012

This paper investigates the effects of applying different input current waveshapes on the performance of a continuous-conduction-mode (CCM) power-factor-correction (PFC) boost pre-regulator. It is found that the output voltage ripple of the pre-regulator can be reduced if the input current is modified to include controlled amount of higher order harmonics. This finding allows us to balance the performance of output regulation and the harmonic current emission when coming to the design of the pre-regulator. An experimental PFC boost pre-regulator prototype is constructed to verify the analysis and show the benefit of the pre-regulator operating with input current containing higher order harmonics.

• Geomechanics and Engineering
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• 제33권4호
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• pp.381-391
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• 2023

The aim of this work is to analyze and predict the wave propagation behavior of the carbon nanotube reinforced composites (CNTRC) beams within the framework of various higher order shear deformation beam theory. Using the Euler-Lagrange principle, the wave equations for CNTRC beams are derived, where the determining factor is to make the determinant equal to zero. Based on the eigenvalue method, the relationship between wave number and circular frequency is obtained. Furthermore, the phase and group velocities during wave propagation are obtained as a function of wave number, and the material properties of CNTRC beams are estimated by the mixture rule. In this paper, various higher order shear beam theory including Euler beam theory, Timoshenko beam theory and other beam theories are mainly adopted to analyze the wave propagation problem of the CNTRC beams, and by this way, we conduct a comparative analysis to verify the correctness of this paper. The mathematical model provided in this paper is verified numerically by comparing it with some existing results. We further investigate the effects of different enhancement modes of CNTs, volume fraction of CNTs, spring factor and other aspects on the wave propagation behaviors of the CNTRC beams.

• Journal of Korean Neurosurgical Society
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• 제64권1호
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• pp.125-135
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• 2021

Objective : This study aimed to validate the Korean version of the Repeatable Battery for the Assessment of Neuropsychological Status Update (K-RBANS). Methods : We performed a retrospective analysis of 283 psychiatric and neurosurgery patients. To investigate the convergent validity of the K-RBANS, correlation analyses were performed for other intelligence and neuropsychological test results. Confirmatory factor analysis was used to test a series of alternative plausible models of the K-RBANS. To analyze the various capabilities of the K-RBANS, we compared the area under the receiver operating characteristic (ROC) curves (AUC). Results : Significant correlations were observed, confirming the convergent validity of the K-RBANS among the Total Scale Index (TSI) and indices of the K-RBANS and indices of intelligence (r=0.47-0.81; p<0.001) and other neuropsychological tests at moderate and above significance (r=0.41-0.63; p<0.001). Additionally, the results testing the construct validity of the K-RBANS showed that the second-order factor structure model (model 2, similar to an original factor structure of RBANS), which includes a first-order factor comprising five index scores (immediate memory, visuospatial capacity, language, attention, delayed memory) and one higher-order factor (TSI), was statistically acceptable. The comparative fit index (CFI) (CFI, 0.949) values and the goodness of fit index (GFI) (GFI, 0.942) values higher than 0.90 indicated an excellent fit. The root mean squared error of approximation (RMSEA) (RMSEA, 0.082) was considered an acceptable fit. Additionally, the factor structure of model 2 was found to be better and more valid than the other model in χ2 values (Δχ2=7.69, p<0.05). In the ROC analysis, the AUCs of the TSI and five indices were 0.716-0.837, and the AUC of TSI (AUC, 0.837; 95% confidence interval, 0.760-0.896) was higher than the AUCs of the other indices. The sensitivity and specificity of TSI were 77.66% and 78.12%, respectively. Conclusion : The overall results of this study suggest that the K-RBANS may be used as a valid tool for the brief screening of neuropsychological patients in Korea.

• 대한안전경영과학회지
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• 제23권2호
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• pp.9-17
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• 2021

As interest in vocational competency development projects increases, support is increasing. In this study, in order to study ways to improve participation in vocational competency development training, related factors are selected and the main factors influencing them are derived. The main factors were influencing factors were identified and ways to improve participation rate of vocational competency development were studied. Variables were selected through prior research, and data were collected and analyzed through in-depth group interviews. Based on factor analysis and reliability analysis, as a result of confirming the factors that influence the plan for improving participation in vocational competency development training by applying the backward stage selection (condition) method of logistic regression analysis, the case of respect for minorities in the 7-point Likert scale The closer to 7 was, the higher the probability of being classified as having never participated, and the other factors except minority respect, Likert scale closer to 7 indicates higher probability of bening classified as having never participated, except for the minority respect factor. Therefore, it was confirmed that lowering the scale of the factor of respect for minority, which is job satisfaction, and increasing the factors of individual characteristics such as annual salary and organizational commitment, training system for job satisfaction, and quality assurance have effects on improving participation rates in vocational competency development training.